Investigating Relationships Between Soil Morphology, Classification, and Hydraulic Properties.

Soils develop as a result of complex interactions between parent material, climate, relief, organisms, and time giving rise to soil morphological properties. The combination of multiple morphological properties of a soil form, in part, the basis of its classification. Morphological properties (e.g., soil structure, pore distribution, and root abundance) have a strong influence over certain hydraulic properties such as total porosity, air-entry value, saturated hydraulic conductivity, available water holding capacity, and field-capacity water content. The goal of this work was to evaluate and quantify the relationships between soil morphology, classification, and soil hydraulic properties using a large subset of the NCSS soil database for the USA. A variety of exploratory multivariate statistical approaches were used to examine relationships among soil structure, field-capacity, water content, effective porosity, texture, bulk density, organic carbon, master and suffix horizon designation, taxonomic classification, and soil climate. Results of this study including implications for modifying soil taxonomy, understanding pedogenic pathways, and developing class-based pedotransfer functions for hydraulic properties will be discussed.